The present invention relates to a method of synthesizing a computer graphics or an image obtained by computer processing (hereinafter referred to as a "CG") and a real image, or more in particular to a method of synthesizing a real image and a CG in an image processing system preferable for efficient synthesis of a real image and a CG.
Conventionally, synthesis of a real image and a CG has been effected by visual environment simulation as described in "Visual Environment Simulation", IPSJ, CG39-1, pp. 1-7, 1989. The visual environment simulation, in which a simulation is made for a case where, for example, an artificial structure is constructed on an actual landscape, has a high utility. For example, an object can be viewed from a point of view that cannot be obtained by other methods such as the use of a miniature model, and the size of an object can be easily changed. Efforts have been made to tackle the visual environment simulation also from the viewpoint of CAD (Computer Aided Design). Such operations (i.e., change in point of view and in shape), however, have been carried out according to a sixth sense based on actual experience or have required information about the point of photographing of the particular landscape, and for this reason, have been unable to be readily performed by general users. On the other hand, as disclosed in "Electronic Studio Settings for Image Production", Proceedings of the Sixth Symposium on Human Interface, pp. 479-486, 1990, and JP-A-61-267182, there is known a method in which such parameters as pan, tilt and zoom in camera operation are recorded at the time of picking up an image and a CG and an image are synthesized by utilizing the parameters in setting a CG. It is not easy for general users, however, to introduce various parameters in camera operation simultaneously with photographing.